Fuel & Tank Level Senders

Measure the internal depth of the tank from the mounting face to the bottom, and order the sender closest to that without exceeding it. Lengths here run from 97 mm to 1100 mm. If no fixed length suits, the VDO adjustable sender covers 150 mm to 535 mm from one unit. Sender length is the specification people most often get wrong.

Match the receiving equipment. Traditional gauges and most generator controllers take a resistive sender; the KUS units are 0-190 ohm (one 1100 mm unit is 0-180 ohm) and the VDO unit is 240-33 ohm, so check which range your gauge or controller expects. A 4-20 mA current loop suits a telemetry unit, PLC or a long cable run in an installation with electrical noise. The CR-6061-1 gives both 0.8-4.5 V and 4-20 mA from one sender.

The direction and range of the resistance swing. A 0-190 ohm sender reads low resistance empty and high resistance full; a 240-33 ohm sender reads the opposite. A gauge calibrated for one will read backwards or off-scale on the other, so match the sender to the gauge or reconfigure the controller input.

Two types. The SAE 5-hole flange, used on the CR-6061-1, the TN series and the 97 mm L6 unit, bolts to a matching flange on the tank top. The 1-1/4 inch BSP thread, used on the KUS stainless units, screws into a threaded boss. Check the tank before ordering: a flange sender will not fit a threaded boss.

Yes. The TN series suction and return senders combine the fuel feed, the fuel return and the level sender in one SAE 5-hole unit, in 150 mm and 420 mm lengths, so a generator tank needs one penetration instead of three.

The KUS stainless units can. They use reed switches in a 316 stainless steel body, and the two-wire versions work as an on-off switch on a digital input, which is how you fit one as a bund high-level alarm on a self-bunded tank.